Sussex County Average 2002 NATA Modeled Air Concentrations Compared to Health Benchmarks

Pollutant

Modeled
Air Concentration (ug/m3)

Health
Benchmark (ug/m3)

Risk
Ratio

%
Contribution from

Major Sources

Area
Sources

On-road
Mobile Sources

Nonroad
Mobile Sources

Background

Acetaldehyde

1

0.45

3

0.005%

2%

21%

5%

72%

Acrolein

0.03

0.020

1.6

0.04%

8%

73%

19%

0%

Arsenic Compounds

0.0004

0.00023

1.8

4%

5%

3%

2%

86%

Benzene

0.9

0.13

7

0.04%

8%

23%

9%

60%

1,3-Butadiene

0.06

0.033

1.7

0.1%

0.02%

20%

11%

69%

Cadmium Compounds

0.00007

0.00024

0.3

1%

24%

0%

0.05%

75%

Carbon Tetrachloride

0.6

0.067

9

0.00007%

0.03%

0%

0%

99.9%

Chloroform

0.07

0.043

1.6

0.002%

17%

0%

0%

83%

Chromium (hexavalent form)

0.0001

0.000083

1.3

3%

4%

4%

0.3%

89%

1,4-Dichlorobenzene

0.06

0.091

0.7

0.007%

24%

0%

0%

76%

1,3-Dichloropropene

0.03

0.25

0.1

0%

100%

0%

0%

0%

Diesel Particulate Matter

1

0.0033

307

0%

0%

33%

67%

*

Ethylbenzene

0.1

0.4

0.3

0.2%

5%

65%

30%

0%

Ethylene Oxide

0.008

0.011

0.7

1%

3%

0%

0%

96%

Formaldehyde

2

0.077

20

0.02%

2%

11%

4%

83%

Methyl Chloride

1

0.56

2

0.001%

0.1%

0%

0%

99.9%

Methyl tert-butyl ether

0.7

3.8

0.2

0.002%

11%

31%

58%

0%

Naphthalene

0.04

0.029

1.5

1%

29%

10%

1%

59%

PAH/POM

0.005

0.0075

0.7

1%

85%

9%

5%

0%

Perchloroethylene

0.08

0.17

0.5

0.1%

22%

0%

0%

78%

1,1,2-Trichloroethane

2.7E-7

0.063

4.2E-6

42%

58%

0%

0%

0%

Chemicals with risk ratios greater than or equal to 1 are
in bold.
Risk Ratios in italics are based on noncarcinogenic effects.
The symbol ug/m3 is micrograms per cubic meter,
the amount (in micrograms) of a chemical in a cubic
meter of air. This is also known as a concentration.
* For diesel particulate matter, onroad and nonroad
concentrations include a model-estimated background
concentration.